Hee hee, that's broken it. The zone boundaries include Broken Hill LGA which all falls inside the Unincorporated Zone, so it makes it look like Broken Hill itself is Unincorporated. How can we have a zone with external boundaries but internal boundaries as well?

Or if we could do a search on Broken Hill it would show it as being within both zones?

Correct, the zone as it appears in GCA includes the other zone which is Broken Hill. The actual LGA shapefile has an inner ring (I think that's what it is) which excludes Broken Hill. I don't know how to use that inner ring in the GCA setup. I'll have to have a look at the files to see exactly what data is in there.

I think you would have to hack the data to make a line from one point on the outer shape to a point on the inner shape and then once it has gone around the inner shape back out again to the same place. That would be my guess, not having worked with this sort of data before.

The data from the LGA shape files for this zone contains these definitions:
outerBoundaryIs
innerBoundaryIs

The outerBoundaryIs defines the "external" shape.
The innerBoundaryIs defines the "internal" shape. i.e. a hole.

Our database is not spatially enabled, so we use code to work out what cache is in what zone. Our code method doesn't handle "holes" so we didn't include them in the data we loaded for that zone (I now remember this after looking into what was going on).

We are upgrading this year. This means we're going to be able to handle "holes" in our geometry's. Wheee! We will have some additional background work to convert use of our linestrings to polygons / multipolygons, but that's an easy enough migration challenge.

Just saw this thread... the NZ "system" is rather informal and non-enforced, and is up to the cache owner as to whether and how they describe where in the country their cache is. Various CO's use different standards, eg. there are a number of Franklin caches that should probably just be Auckland, and the Central Plateau region doesn't formally exist, but works better for caches in that area than Waikato, Bay of Plenty or Wanganui, which they would otherwise be classified as. Even in the informal way we do it here, it makes it really easy for us to quickly decide when looking at the new cache listings, etc, whether a cache page is worth opening and looking at or not.